13F Filings Explained: What They Show, What They Hide and How to Read One

The third-quarter 2026 13F filings are due on Monday, November 16, 2026, according to the SEC’s own Form 13F FAQ. On that day and in the days before it, thousands of institutional managers will publish what U.S. stocks they held on September 30. Headlines will follow about which famous fund bought which mega-cap. Most of those headlines describe trades that are already six weeks to four and a half months old. A 13F is one of the best free data sets in investing and one of the most misread. If you want the bigger picture first, start with our hub on institutional money flow.

What is a 13F filing?

A 13F filing is a quarterly report of long equity holdings that institutional investment managers file with the SEC under Section 13(f) of the Securities Exchange Act. The form is called Form 13F, and the holdings report is filed as form type 13F-HR on EDGAR.

Section 13(f) exists to make large institutional holdings public. The SEC implements it through Rule 13f-1, which requires a report from every manager that exercises investment discretion over enough “Section 13(f) securities.” The report has a cover page, a summary page with the number of holdings and their total value, and an information table with one line per security: issuer, class, CUSIP, market value, number of shares, whether it is a put or call, investment discretion and voting authority.

What makes a 13F valuable is that it is mandatory and comprehensive within its scope. Hedge fund advisers, mutual fund companies, banks, insurers, broker-dealers and pension managers all file if they cross the threshold, so you can see the long side of almost every large institutional portfolio in U.S. stocks. What limits it is that scope: long positions only, U.S.-listed securities only, quarter-end only.

Who has to file a 13F, and what is the $100 million threshold?

You must file a 13F if you are an institutional investment manager that exercises investment discretion over $100 million or more in Section 13(f) securities on the last trading day of any month in a calendar year.

Three details in that sentence matter. First, “investment discretion” means the power to decide what to buy or sell for an account, so the filer is the manager, not the fund’s investors. A family office, an RIA running discretionary accounts or a hedge fund adviser can all qualify. Second, the test is only on Section 13(f) securities, which the SEC lists each quarter in its Official List of Section 13(f) Securities. The SEC says the list “primarily includes U.S. exchange-traded stocks.” Bonds, cash and futures don’t count. Third, crossing the line on any month-end triggers the obligation. Per the SEC Form 13F FAQ, the first report is for the fourth quarter of that calendar year.

For options, the Form 13F instructions say only the value of the options themselves counts toward the $100 million test, not the value of the shares underlying them. A manager with $80 million of stock and $30 million of listed call options crosses the threshold; the underlying exposure of those calls doesn’t matter for the test.

What is the 13F filing deadline?

A 13F is due within 45 days after the end of each calendar quarter. When day 45 falls on a weekend or holiday, the filing is due on the next business day.

That gives four deadlines a year, in mid-February, mid-May, mid-August and mid-November. The SEC publishes the exact dates in its FAQ. For the next four quarters they are:

The lag is the single most important thing to understand about a 13F. The holdings are a photo of the last day of the quarter, released up to 45 days later. A manager who bought a stock on July 1, 2026 and held it through September 30 could legally keep that position private until November 16: 138 days. Nothing in the rule requires an earlier filing.

What does a 13F show, and what does it leave out?

A 13F shows long positions in U.S. exchange-traded securities on the Official List, valued at quarter end. It leaves out short positions, options the manager wrote, most non-U.S. holdings and anything that says when or why a trade happened.

The SEC’s FAQ is direct on the biggest gap: “You should not include short positions on Form 13F,” and shorts are not netted against longs either. Options the manager wrote, such as covered calls or short puts, are not reported. Long puts and calls that the manager holds can be reported, and the Form 13F instructions require most columns for an option to be given in terms of the underlying shares, with “PUT” or “CALL” marked. This is why you sometimes see a headline that a fund owns a giant position in a stock when in fact it owns puts on it: the share count on the put line is the number of shares underlying the contracts, and the put is a bearish bet.

Shares of foreign companies appear only if they trade on a U.S. exchange. Treasuries, corporate bonds (other than certain listed convertibles), cash, futures and swaps do not appear at all. Managers may also leave out tiny holdings: the instructions allow omitting a position of fewer than 10,000 shares and less than $200,000 in value, both conditions together. Finally, the value column is a quarter-end market value. There is no purchase date, cost basis or average price.

How do you read a 13F on EDGAR, step by step?

You read a 13F by finding the 13F-HR filing on EDGAR, opening the information table and comparing it with the prior quarter. The comparison is where the information is.

1. Find the manager. Go to EDGAR full-text search or EDGAR company search and type the management company’s legal name, which is often different from the fund’s marketing name.
2. Filter to form type 13F-HR. 13F-HR is the holdings report. A 13F-NT (notice) means another manager reports the holdings, and 13F-HR/A is an amendment, which can add positions that were held back under confidential treatment.
3. Open the information table. Each line is one class of one issuer with one type of discretion. The same stock can appear on several lines if it is split by discretion or by put and call.
4. Check the summary page. Note the entry total and value total, and whether the box for confidential treatment requested is checked. If it is, something is missing.
5. Separate shares from options. Lines marked PUT or CALL show the underlying share count, not shares owned.
6. Compare with last quarter. New lines, exits, and changes in share count (not value, which moves with price) tell you what the manager did during the quarter.
7. Weigh by portfolio share. A $50 million position is a conviction bet for a $500 million fund and noise for a $500 billion manager.

For more than a handful of managers, the SEC’s Form 13F data sets package every filing’s information table for bulk analysis.

What does a worked 13F example look like?

Here is an illustrative reading of one fund’s two consecutive 13Fs, to show how much interpretation each line needs. The fund, the positions and the prices are hypothetical.

1. Stock A. The share count rose by 500,000. You know the fund owned 1.5 million shares on September 30. You don’t know whether it bought them at the low of the quarter or the high, and you don’t know what it did in the six weeks before the filing.
2. Stock B. The line disappeared. That is usually a sale, but it could also be a position reported under a confidential treatment request, which would appear later in an amendment.
3. Stock C. The line says PUT. Twenty thousand put contracts at 100 shares each show as 2,000,000 shares of underlying. A careless screen reads this as a large long position; it is the opposite.
4. Stock D. No change on the 13F, but the fund could have shorted the stock or entered a swap that offsets it. Neither appears.

The pattern: additions and new long lines in share terms are the most reliable signals; anything involving options, exits or apparent inactivity needs a second source.

Can you copy hedge fund 13Fs and make money?

Copying 13Fs is possible but structurally handicapped: you trade late, you see only half of each position’s risk, and you never see the exit until the next quarter.

Three problems compound. Staleness: by the filing date, the information is at least 45 days old, and up to about 135 days for a position opened at the start of the quarter. Missing hedges: a long-short equity fund’s long book without its short book is a different portfolio with a different risk, as our guide to gross vs net exposure explains. Turnover: for quant, multi-strategy and event-driven funds, positions often change in days or weeks, so the 13F is a snapshot of a portfolio that no longer exists. Our overview of hedge fund strategies for retail investors covers which styles leave useful footprints.

Where 13Fs work better: concentrated, low-turnover managers who hold positions for years; changes in ownership across hundreds of managers at once; and spotting crowding, where many funds own the same names. That last use is the subject of our page on hedge fund crowded trades.

What is 13F confidential treatment?

Confidential treatment lets a manager omit specific holdings from the public 13F while the SEC reviews a request, usually to protect a position that is still being built or sold.

The SEC’s FAQ says confidential treatment is available under the Freedom of Information Act, and the Form 13F instructions say requests follow Rule 24b-2. The summary page has a box marked “Confidential Treatment Requested.” When it is checked, the public filing is incomplete by design. Holdings withheld this way can be added later in an amended filing (13F-HR/A). Separately, holdings that identify securities held for a natural person or certain estates and trusts must be submitted through the confidential process. For a reader, the practical point is simple: when that box is checked, don’t treat an absent line as a sale.

How is Rule 13f-2 and Form SHO different from a 13F?

Rule 13f-2 is the SEC’s short-position counterpart to the 13F, but it is not in force yet: after court-ordered review, the SEC has extended compliance to January 2, 2028.

The SEC adopted Rule 13f-2 and Form SHO on October 13, 2023. Managers meeting certain thresholds would file Form SHO with the SEC within 14 calendar days after each month end, and the SEC would publish aggregated data per stock rather than each manager’s shorts. The original compliance date was January 2, 2025. The SEC extended it to January 2, 2026 in February 2025. On August 25, 2025, the Fifth Circuit remanded the rule, without vacating it, so the SEC could consider its cumulative economic impact. On December 3, 2025 the SEC extended the exemption again, in Release 34-104303, so the first Form SHO reports would cover January 2028. As of October 2026 that is where it stands.

Until then, the public view of short positioning comes from exchange and FINRA short interest data, which is aggregated per stock and published twice a month. Our guide to short interest covers how to read it.

What do 13Fs mean if you hold concentrated company stock?

For an executive or tech employee with a large position in one stock, a 13F is a map of who else owns your stock, and that tells you something about how it may trade under stress.

If your employer’s stock is among the most widely held names in hedge fund 13Fs, it is exposed to crowding: when those funds cut risk at the same time, the selling arrives together, unrelated to your company’s fundamentals. If it is mostly held by index funds and long-only managers, it tends to trade more with the market. Neither changes your plan, but both inform how much downside protection makes sense and when. A collar on concentrated stock is one way to hedge a crowded name without selling.

Two more points for insiders. Your own trades are disclosed far faster than any 13F: officers and directors file Form 4 within two business days, covered in our guide to 13D, 13G and Form 4. And if you sell under a pre-arranged plan, the timing rules of 10b5-1 plans apply regardless of what institutions are doing. Watching 13Fs is research; it is never a reason to trade outside your company’s window.

What is a checklist for using 13F data?

1. Note the snapshot date and the filing date; count the days between them.
2. Check the summary page for the confidential treatment box.
3. Separate share lines from PUT and CALL lines.
4. Compare share counts, not values, with the prior quarter.
5. Size each position against the manager’s total reported portfolio.
6. Ask what the fund’s style hides: shorts, swaps, non-U.S. holdings, fast turnover.
7. Look for faster confirmation in Schedule 13D/13G or Form 4 filings before relying on a signal.
8. Use 13Fs for ownership and crowding questions, not for entry and exit timing.

Frequently asked questions

Key takeaways

1. A 13F is a quarterly list of long U.S.-listed holdings filed by managers with $100 million or more in Section 13(f) securities.
2. It is due 45 days after quarter end; the third-quarter 2026 deadline is November 16, 2026.
3. It omits short positions, options written, non-U.S. listings and the timing of trades, so it can make a hedged fund look long.
4. Copying 13Fs means trading on information that can be four months old for a position bought early in a quarter.
5. 13Fs are most useful for slow questions: who the long-term holders are and how crowded a stock is.
6. Short-position disclosure under Rule 13f-2 and Form SHO is delayed until January 2028 reporting.

Sources and method

1. SEC, Frequently Asked Questions About Form 13F — who files, 45-day deadline, 2026–2028 due dates, shorts and written options excluded, de minimis rule
2. 17 CFR 240.13f-1 (Rule 13f-1) — $100,000,000 threshold, investment discretion, timing
3. SEC, Form 13F and General Instructions — information table columns, options reported in terms of the underlying, confidential treatment
4. SEC, Official List of Section 13(f) Securities — quarterly list of reportable securities
5. SEC, Form 13F data sets — bulk 13F data
6. SEC, EDGAR full-text search — finding 13F-HR filings
7. SEC press release 2023-188 — adoption of Rule 13f-2 and Form SHO, October 2023
8. SEC Release 34-104303 (Federal Register, Dec. 2025) — Form SHO compliance extended to January 2, 2028; Fifth Circuit remand

Chart 1 uses the SEC’s published 13F due dates; the 138-day figure is Proflex arithmetic from July 1 to November 16, 2026. Chart 2 summarizes the SEC Form 13F FAQ and Form 13F instructions. Chart 3 is a Proflex framework. The worked example uses an illustrative fund and illustrative prices, not real holdings. Deadlines and the Form SHO status are as of October 2026.